Scammers holding PCs to ransom

People needed to take more responsibility for their own safety. Photo / Thinkstock

Computer users are being warned of a new scam that holds a user to ransom by locking his or her machine and asking for money.

The scam, dubbed "Ransomware", usually gets through outdated software such as Java.

A message appears on a computer screen informing a user it has been locked and the only way to unlock it is to pay a fine.

There are different types of Ransomware, with some showing the NZ Police logo and fines ranging from $100 to $5000.

More than 100 cases have been reported to NetSafe this year and the internet safety group is calling on people to protect themselves by making sure their gear is up to date.

This is NZ Cyber Security Awareness Week and NetSafe's cyber security programme manager, Chris Hail, said it was the perfect time to get people thinking about things they could do to prevent cyber attacks.

"We've had all sorts of people - from home users to small businesses - contact us about this latest scam," Mr Hail said. "It really is worth making sure all your anti-virus software is up to date, so you don't have to spend a couple of hundred dollars later to fix the problem."

Mr Hail, who deals with victims on a daily basis, said being attacked in such a way affected people deeply.

"I had one woman from Rotorua, in her 70s, who was really upset.

"She said it felt like she'd been burgled - like someone had come into her house and stolen something from her."

Sydney-based Google spokesman Johnny Luu is in the country working to help Kiwis better understand how to keep themselves safe online.

He said the giant company had invested hundreds of millions into web safety and had hundreds of security experts working around the clock to identify unsafe web pages.

But people needed to take more responsibility for their own safety.

"One of the common mistakes people make - regardless of age - is that they're not using a strong enough password or different passwords across different sites.

"We recommend using different passwords across different websites."

Mr Luu said over the years Google had worked to make sure petty but at times costly scams did not get through to customers' emails.

"But what we're seeing more of are phishing scams, where criminals are pretending to be someone you know.

"They send an email with an attachment and when you download the file, it stores viruses on to your computer."